Creating meteorological maps in R

[Thanos64]

Hello,
I need some help creating maps showing the fluxuation of some climate indices in the country of Greece.
For example, I have a data frame containing the dtr of 6000 gridpoints in Greece with their coordinates
and I want to make a map like this one

I followed the tutorial about the sp and sf packages however they dont seem to work.
Any help or thought on how I can do it, is appreciated

[Fer]

What format as the data you want to plot?
I have made similar plots to the one shown using raster

[jlacko]

There are formats to facilitate this; NetCdf comes to mind.

On the other hand for an existing coordinate / value dataset ggplot2::geom_tile() might be easier.

Have a look at code in this older question; the use case is similar...

How to crop gridded data with shapefile

I don't know how to upload the shapefile, so the data, code and figure are shown below. Due to the large volume of the DFgrid file, I only included part of the dataset, but the dataframe structure is the same. The DFgrid covers whole shapefile border, but some grids are even outside of the border. I can only draw the two figures separately. How to crop the DFgrid file to the shapefile border, so that all grids are inside of the border and have perfect curves at the verge? I would really appreciate your help. ######################### example file library(ggplot2) DFgrid= data.frame( lon=c(59.25, 59.75, 60.25, 60.75, 61.25, 61.75, 57.25, 57.75, 58.25, 58.75, 59.25, 59.75, 60.25, 60.75, 6…

[Thanos64]

My original data (containing surface temperature) were NetCdf files. However, in order to calculate those indices I had to modify those files into .xts and then the final data frame containing the dtr, the longitude and the latitude is numerical.
I tried using raster but if I'm not mistaken it requaries .nc files so unless there is a way to save the final data frame as .nc, I cant use it

[Thanos64]

Thank you, I tried that approach and got some results as shown in the picture

Although I have doubts about the data cause of the really low dtr in the southern part, but I assume that has to do more with quality control and less with programming

The code I used was the following (dtr_15_19 is the data frame with dtr values and coordinates and dtr15_19 only the dtr values) :

my_year <- theme_bw() + theme(panel.ontop=TRUE, panel.background=element_blank())

my_fill <- scale_fill_distiller('',palette='Spectral',
limits = c(1,13),breaks=c(1,5,9,13))

fig = ggplot(dtr_15_19 , aes(y=lat, x=lon, fill=dtr15_19 )) + geom_tile() + my_year + my_fill+
coord_quickmap(xlim=c(19, 30), ylim=c(34, 42))+
borders('world', xlim=c(19, 30), ylim=c(34, 42), colour='black')+
xlab('Longitude (°E)')+ ylab('Latitude (°N)')+
theme(panel.grid=element_blank(),
panel.border = element_rect(colour = "black", fill=NA,size=.7))+
labs(title = "Mean DTR in period 2015-2019")

print(fig)

EDIT:
I did the quality control and I got my results! Thanks a million!!